The subject invention pertains, in general, to improvements in instrument transformer performance; and, more particularly, to the combination of a transresistance amplifier with a current transformer for the purpose of terminating the current transformer with an active load element which virtually short-circuits the transformer while providing an output voltage which is proportional to the transformer current of interest.
Ideally, an instrument current transformer should operate with its secondary short-circuited. However, this would mean that the voltage across the secondary would be zero and it would not, ordinarily, be possible for the secondary to supply an output voltage proportional to current in the primary; the voltage output being required for metering purposes, for example.